Neutrons are neutral particles which are not directly detectable electronically. Spectral information of neutron fields is often desired to be characterised, such as by surveying the neutron radiation environment at flight altitudes or in nuclear facilities. To measure a neutron spectrum Bonner sphere spectrometers are often used. A Bonner sphere spectrometer (BSS) comprises a plurality of spherical detectors, often six to fourteen, each of which includes a thermal neutron detector surrounded by a moderator of various thicknesses. The thickness of the moderator provides each detector with a different response function to neutron energy. A thicker moderator provides the detector with an increased response to higher energy neutrons but a reduced response to lower energy neutrons. After being exposed to a neutron field, readings of the spheres are used in an unfolding process to retrieve neutron spectrum information. However, BSSs are large and heavy, which restricts their usage in many applications.
It is an object of embodiments of the invention to provide a neutron detector and spectrometry system which is physically small and from which neutron spectrum information may be derived.
It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.